NASA Handrail Clamp Assembly Challenge

About this Challenge

NASA is seeking to challenge the GrabCAD Community by sponsoring an open competition where participants utilize the new additive manufacturing capability on the International Space Station (ISS). The competition will be to design a complementary Handrail Clamp Assembly (HCA) which is currently utilized by astronauts to provide rigid mounting locations required in a microgravity environment for normal daily operations. The complementary HCA design will be referred to as the CHAMP (Clamp for Handrail with Additively Manufactured Parts). The printed part will be analyzed to further our understanding of the effects of microgravity on the fused deposition method of manufacturing.

Handrail Clamp Assembly (HCA) Overview

The HCA is currently utilized on the ISS to provide a seat track interface by creating a structural connection on the ISS handrail located throughout the station. It should be noted that the seat track interface is what needs to be reproduced in the CHAMP. The seat track is consistent with those utilized on commercial airlines. The interface does NOT have to be considered a separate feature. It must however provide the interior cross section and access to that interior profile consistent with the provided dimensions so as to be a functional connection point for the mating adaptor (must be at least 1.750” long with 0.785” holes, etc.). The cross section should be considered a smooth and consistent surface. The following picture show the HCA as well as the HCA in-situ.

Addition to NASA GrabCAD Challenge (as of January 22)

The overall function of the clamp assembly is to provide a seat track interface in order to mount hardware onto the handrails. This Challenge is not focused on creating a carbon copy of the existing ISS handrail clamp, but to design a device that attaches to the handrail and provides a seat-track-like interface specifically optimized for 3D printed material. The handrail itself does not need to be redesigned. The existing seat track is metallic and has small features with high strength capability that would be very difficult to replicate with ABS plastic. While a new seat-track-like device could be designed the goal is to design the device to interface with the Stud specified in MS33601, available
here. Please note we understand the spec is outdated, but the NASA interfacing components meet this spec.

The current clamp assembly (shown for reference) has a required kick load of 125 lbf. We understand that this requirement may be unfeasible given ABS material and the size limitations, but try to make the designs as strong as possible. Maximum loads from mechanical properties we have obtained so far from ABS parts made by FDM are as follows:

Z Tensile (build direction): 50 lbf,

XY Tensile (-45,45 layup): 121 lbf,

XY Tensile (0,90 layup): 120 lbf,

Flex (-45,45): 359 lbf,

Flex (0,90): 323 lbf,

Z Compression: 1433 lbf,

XY Compression (-45,45): 1316 lbf,

XY Compression (0,90): 1457 lbf.

A factor of safety is not accounted for with the listed numbers. Crew tools on the ISS must have a FOS of at least 2.

Seat Track Explanation

We understand that many designs are works-in-progress, but we wanted to make sure that everyone in the challenge was aware of how seat track functions. Please take a moment to watch this video showing how the stud and seat track connect. Your design should allow for the stud fastener to be attached and secured. Thanks again to Philip LaRoach for finding and sharing this video.

Requirements

You must include:- STL version
- Description of your design

You are encouraged to include:- Native CAD file format
- STEP or IGES version
- Rendering

CHAMP figures of merit:The following figures of merit will be used by NASA to determine which CHAMP design is determined as the most successful and is to be printed on the ISS.
1. Total Material Usage
a. ISS has established a maximum amount of ABS plastic allowed within the pressurized volume due to outgassing issues.

2. Number of prints required to complete each CHAMP
a. Astronaut time is valuable and sparse on the ISS

The CHAMP must at minimum meet the following requirements:1. Shall be capable of providing a rigid connection to the handrail as defined above.
2. Shall provide a seat track interface as defined above.
3. Shall conform to the following sharp edge human factors
- Exposed edges 0.25 in thick or greater shall be rounded to a minimum radius of 0.12 in.
- Exposed edges 0.12 to 0.25 in thick shall be rounded to a minimum radius of 0.06 in.
- Exposed edges 0.02 to 0.12 in thick shall be rounded to a full radius.
- The edges of thin sheets less than 0.02 in thick shall be rolled or curled.
4. Envelope
- Shall not extend beyond 1” from the cross-sectional perimeter of the handrail once installed and considered ready for use.
- Shall not extend beyond 5” along the handrail long axis.
5. If multiple parts are utilized, each much connect without the need of additional tools or materials. This applies to assembly, installation, removal and disassembly.
6. All design models shall be delivered as .stl files with a suitably fine mesh accurate enough to convey design intent (a .stp file will be required from the top three place designs as well).
7. Directions specifying build orientation shall be provided along with the design models. Axis nomenclature is found below in the ISS Additive Manufacturing Capability section.

Rules

ENTERING THE COMPETITIONThe Challenge is open to everyone except employees and families of GrabCAD and the Sponsor. Multiple entries are welcome. Team entries are welcome.

By entering the Challenge you:
1. Accept the official GrabCAD Challenges Terms & Conditions.
2. Agree to be bound by the decisions of the judges (Jury).
3. Warrant that you are eligible to participate.
4. Warrant that the submission is your original work.
5. Warrant, to the best of your knowledge, your work is not, and has not been in production or otherwise previously published or exhibited.
6. Warrant neither the work nor its use infringes the intellectual property rights (whether a patent, utility model, functional design right, aesthetic design right, trademark, copyright or any other intellectual property right) of any other person.
7. Warrant participation shall not constitute employment, assignment or offer of employment or assignment.
8. Are not entitled to any compensation or reimbursement for any costs.
9. Agree the Sponsor and GrabCAD have the right to promote all entries.

Entries are automatically given the tag "handrailclamp" when uploading to GrabCAD. Please do not edit or delete this tag. Only entries with valid tag will participate in the Challenge.

AWARDING THE WINNERSThe sum of the Awards is the total gross amount of the reward. The awarded participant is solely liable for the payment of all taxes, duties and other similar measures if imposed on the reward pursuant to the legislation of the country of his/her residence, domicile, citizenship, workplace, or any other criterion of similar nature. Only 1 award per person.

All winners will be contacted by the GrabCAD staff to get their contact information and any other information needed to get the prize to them. Payment of cash awards is made through PayPal. All team awards will be transferred to the member who entered the Challenge.

We will release the finalists before the announcement of the winners to give the Community an opportunity to share their favorites in the comments, discuss concerns, and allow time for any testing or analysis by the Jury. The Jury will take the feedback into consideration when picking the winners.

Winning designs will be chosen based on the Rules and Requirements.
- This Challenge ends on February 17, 2015 (11:59pm UTC).
- Winners will be announced by March 17, 2015.

Void where prohibited.

Prizes

$2,000 total prize pool

1st Place

$1,000 cash

2nd Place

$500 cash

3rd Place

$250 cash

4th Place

$150 cash

5th Place

$100 cash

About In Space Manufacturing

The International Space Station’s 3-D printer has manufactured the first 3-D printed object in space, paving the way to future long-term space expeditions. The object, a printhead faceplate, is engraved with names of the organizations that collaborated on this space station technology demonstration: NASA and Made In Space, Inc., the space manufacturing company that worked with NASA to design, build and test the 3-D printer.

This image of the printer, with the Microgravity Science Glovebox Engineering Unit in the background, was taken in April 2014 during flight certification and acceptance testing at NASA's Marshall Space Flight Center in Huntsville, Alabama, prior to its launch to the station aboard a SpaceX commercial resupply mission. The first objects built in space will be returned to Earth in 2015 for detailed analysis and comparison to the identical ground control samples made on the flight printer prior to launch. The goal of this analysis is to verify that the 3-D printing process works the same in microgravity as it does on Earth.

The printer works by extruding heated plastic, which then builds layer upon layer to create three-dimensional objects. Testing this on the station is the first step toward creating a working "machine shop" in space. This capability may decrease cost and risk on the station, which will be critical when space explorers venture far from Earth and will create an on-demand supply chain for needed tools and parts. Long-term missions would benefit greatly from onboard manufacturing capabilities. Data and experience gathered in this demonstration will improve future 3-D manufacturing technology and equipment for the space program, allowing a greater degree of autonomy and flexibility for astronauts.

a. ISS has established a maximum amount of ABS plastic allowed within the pressurized volume due to outgassing issues.

“The HCA is currently utilized on the ISS to provide a seat track interface by creating a structural connection on the ISS handrail located throughout the station. It should be noted that the seat track interface is what needs to be reproduced in the CHAMP. “

More details please, is the goal to design the whole mechanism, as shown in blue, with the lever also, or just the track that is mounted to it, opposite the handrail?

Do the hand rails need redesign or design for 3dp fdm also? I’m assuming you will be keeping the aluminum hand rails intact as they are on the station.

“The seat track is consistent with those utilized on commercial airlines. The interface does NOT have to be considered a separate feature 1.02” wide and 0.44” tall.”

What does this mean, can you elaborate? Thanks.

It must however provide the interior cross section and access to that interior profile consistent with the provided dimensions so as to be a functional connection point for the mating adaptor (must be 1.750” long with 0.785” holes, etc.). The counterbore holes (dimensions removed) are NOT required.

The “mating adapter”, being the anodized blue gizmo seen in the pictures?

From what I understand, there are three parts that make up the HCA,

The Handrail ( oval shaped tube, looks like ano alum)
The Clamp mechanism ( the part that clamps onto the rail using a lever)
The seat track (the tracked part attached to the clamping mechanism)

The description is not very accurate. I understand that the dimensions 1.02x0.44 and 1.750 with the 0.75 holes are for the seat track. The clamp has the dimensions that you want while is under the restrictions and can be adapted to the tube.

I think this is not possible (printing without support), because the melted plastic is pushed through the nozzle, and then there is the force that will push the plastic aside. this pushed plastic will not levitate in one place... i hope so... :)

But out of the nozzle the ABS cools, then it cringe/shrinks. Get stiff and less
flexibility. Would that not be enough in combination with the nozzle, which also pulls on the cooling filament while printing.

We've updated the page with new information based on your questions. If you don't see an answer to something you're wondering, apologies for missing it. Feel free to point out what needs more clarification. Thanks for all the great feedback and entries so far! Once we get all the details up, we'll start giving some individual feedback, so get your concepts up to allow for more iterations.

Sorry for the delay in responding, please note the update made to the challenge description on 1/22 we hope this will provide answers to most of the comments. We are working through the rest of the comments now and will post additional responses if we feel they were not addressed in the 1/22 update.

Here are my max. external dimensions of the clap in mm:
Dimensions of the NASA Handrail ClampCould you please answer my questions?
1. Max. amount of ABS plastic for one print in gram [g]?
2. The seat track has to be 1.02” (44,45 mm) long?
3. Are the holes (0,785”) needed in the seat track if the interior cross section can be accessed on both sides?

Anyone from NASA, is there a overhang threshold for the ISS 3D printer? Most ABS printers can do up to 45° without support material, but I would like to know if there are restrictions specific to the ISS printer. Thanks.

Michel Schon:
1. For this challenge, we are not constraining the print time or quantity of ABS permitted.
2. Sorry for the confusion, there are no length requirements on the seat track. We had some last minute changes to the images posted that we did not get properly reflected in the written explanation. The device must fit within the Envelope requirements specified above (seat track included).
3. Yes the hole is needed. Please take a look at the Youtube video and Aircraft Seat Track links above for a visual of how seat track works. Please let us know if you still have a question.

Hevi: Slic3r can be used to generate the g-codes. The company Made in Space generated all the g-codes for the parts built so far. They might have their own slicing software but they've also used slic3r.

Hevi:
To verbally explain the max external dimensions... take a 1" wide sweep around the external profile of the handrail end view (oval view) now extrude that 5"... that's your max envelope for everything (clamp, seat track, etc.). During installation pieces of the clamp are allowed to travel outside this volume, but once installed all of the device must be within this volume. Perhaps a picture really is worth a thousand words...I'll see if I can get a sketch uploaded to the challenge.

Jonathan: I'm not sure off hand what the maximum allowable amount of ABS on the ISS is but what we launched is well under that limit. There is no set time limit, but the longest build so far was just under 4 hours. The printer has it's own filtration and it is also set up inside the Microgravity Science Glovebox which has its own filters so there is no ABS offgassing into the main cabin.

Drew Hood:
Thanks for the quick answer. But I am still not sure about the length of the seat track: How many holes are needed for the positioning (fixing)? In the video only one hole in needed but other fittings may need more holes?

Jonathan:
From the HAC overview, "The seat track is consistent with those utilized on commercial airlines. The interface does NOT have to be considered a separate feature." So in the video you can disregard the thru holes in the track used for mounting. The track can be integrated or attached to your design however you see fit, but it must all be 3D printable. Hope this helps. Let me know otherwise.

But if the track is 3D printed, it won't stand up to the forces involved.....that's why it's made from machined aluminum....will the naughts be attaching heavy objects to it or just small objects to it?, actually I guess weight doesn't matter haha, it's space.....but we could talk in terms of forces I guess then. Like if the attached object was hit by something with much more mass, the 3D printed track would snap..... if this was already discussed and explained, I apologize, a lot of info to talk into account.
Jon-

Yep you're on the right track! We know it won't be as strong as the aluminum track and could be the weak spot of all the designs, structurally... but that's part of the challenge :)
Are there novel ways to reinforce the track?
What kinda of loads can it take?
What kind of performance can we get out of a 3D print optimized design?

excuse the dumb question, i dont really understand the +- tolerances are they supposed to be included for example if .8 + .020 should the measurement be .8 or .82 or in between? im a just for fun user and havent been to school for any of this stuff but im excited to participate in such a big challenge.

No keerthi, you have to design it yourself in any CAD tool such as Solidworks, Catia, Pro-E, etc. By this website we share our work to all the fellow engineers. And also please ask challenge related questions here, for any doubt about this website you may ask Sara Sigel

Jonathan:
For the bigger parts we've built so far we've used sparse infill to cut down material use and print time, but we haven't evaluated how infill percentage effects material strength yet. Short answer, we have no preferred method yet.

Gaps can be wider than the resolution. Once we get the parts back to study we'll have a better estimate of what kind of gaps it can do with accuracy but for now let's say maybe not much more the 1/2 inch. It may be able to do longer gaps with domes or arches.

- Exposed edges 0.25 in thick or greater shall be rounded to a minimum radius of 0.12 in.
- Exposed edges 0.12 to 0.25 in thick shall be rounded to a minimum radius of 0.06 in.
- Exposed edges 0.02 to 0.12 in thick shall be rounded to a full radius.
- The edges of thin sheets less than 0.02 in thick shall be rolled or curled.

So, would that mean we would have to radius the edges of the clamp itself? if it's printed on a flat bed, it's better if the bottom edge is left without a radius...Can this be explained a little further..?

Hey Jonathan,
Thanks for the reply, lets say that I want to print a hinge. What should I use as the minimum gap between the parts of the hinge? Because too much gap would create a play. Hope my question is clear :)

@ Rash, .025" gap is what I use and is recommended as a standard across the board, but it goes on a printer by printer basis. That's what I used for my parts and they come out perfect, not too much play, not too stuck....they will be a little stuck, you just break them free and then they will pivot, move rotate, whatever.

for snug fit against a defined dimension, I use .014-.016", or about .4mm. But again, that's printer specific. So let's say I'm printing a rod which I want to have a nice sliding snug fit in a hole that is EXACTLY 1" ID, then I design my printed part with .985" OD or (1"-.015").

Phil, up to you. Usually if you go out and tangent into something significantly different then you would upload that as a second entry.... if you're just making small mods to an existing model, keep it all under one submission.

Jonathan:
The requirements for the radiused edges are in accordance with HFIT (Human Factors Implementation Team) requirements so sharp edges should be radiused. In general, yes, it is better to have a completely flat bottom surface however the machine on the ISS prints directly onto a tray and at least one edge needs to have a radiused or angled corner in order to pry it off the plate. For taller parts it's not that much of an issue though.

For the seat track dimensions you can modify them as needed, as long as it can interface with the stud dimensions shown on the everyspec link.

Sorry, I misunderstood your question. Features less than 0.04" is about where this printer starts losing accuracy. For moving parts it can go as low as about 0.01" and still have a gap. It may be a little stuck but with some effort the parts will break apart.

A request to new entries please don't repeat or copy the work of old entries as it will effect the Honor code we follow all the time. There is always something creative to make for a single task! Thank You

Some of the entries (I won't mention the Engineers name) are having a lot of similarities to the old entries. Its just an request which if followed then good and if not then I don't have any problem. Just many of the Engineers submitted great design Entries and I don't wish others to simply copy and make alteration. Just a thought!

@Hevi and Jonathan
For this challenge we are not constraining the print time or quantity of ABS permitted. As mentioned in the figures of merit section we are interesting in how much ABS is used to print ones CHAMP design, but there is no "max allowed amount" for the CHAMP. An example to help clarify, the less ABS the design uses means that more CHAMPS could be printed, while staying under ISS established ABS limits. Hope this helps.

Abhijeet Das, I'd like to comment on this. I have been working on a design since this competition launched on the 20th of January. Today someone uploaded a design that has many things in common with the design I've been working on. When I upload my design it will appear as though I've copied and altered another already uploaded design, but in reality I've been 3D printing, remodeling, and refining my design to best meet the requirements. I'm not trying to nit pick but giving the competition a deadline but then displaying entries before the deadline makes the competition about speed rather than the quality of the entries. This does not seem like the best method for running a competition, especially in the context of NASA.

Joseph Corsi I really appreciate your way of working for this competition, it's really good but not all the Engineers participating in this event have that particular resource to refine their design in your manner. I and many of the engineers used software as the only tool to design and optimize the Champ model for NASA. But using 3D printer will give you satisfaction to your design. NASA needs the best design and also we want to deliver them the best but you should keep in mind its a challenge so if what you say is true then it could be taken as point that you might have copied some features from the already submitted entry. Best way to prevent that is to submit some proof of some sort or submit your idea in paper sketch before hand. No doubt NASA experts will scrutinize each and every designs and will select winners wisely. Also those who did 3D printing of their designs, I really praise there effort for achieving satisfaction.

Hevi:
Currently ISS Operations do not allow support material to be printed with the part. The printer only has 1 extruder tip anyway. I'm not sure if that restriction will be lifted in the future but for now it poses a risk to ISS crew. I apologize if that wasn't made clear in the requirements.

Quincy Bean 3Thanks, but... I wanted to say that you can print support with the same printer nozzle and same material. It is just an option in slicer software. The point of my question is - let's say Elena prints something and slicing software adds some kind of support >>> http://tinyurl.com/nmlcr5o <<< so now she needs to remove it;is this kind solution acceptable?

I've been competing in quite a few competitions, mostly here on GC and others and there are a few factors to consider, but it's a sketchy topic for sure...

One thing I try to do to lock in a design is put up a sketch as soon as I can outlining my thoughts and the direction I want to go in. Like Josh says, there's often only so many ways to design something so it comes down to EXECUTION, PROCESS, QUALITY, PRESENTATION and often times, if they're similar enough, submission date.

You can usually tell when someone waits until the end of the contest to "snipe" an existing design, add improvements to it etc. basically just mooching off others process and work.

There's a difference between that, and finding inspiration from another design and building off of that. BUT again, it's a sketchy area at best, depends on what is being designed also.

With something like this, a clamp design....variation in design is pretty tough to achieve, you can expect more overlap. It's going to come down to who posted what first along with the other factors I mentioned above.

Nahh... I will add some comment... Jonathan I do almost same thing, I "lock" some concept by posting my entries. It is almost always "work in progress" project. But when you are working on some new designs someone else is improving your WIP project. You show the path how you were thinking and someone adds few things (sometimes obvious) and you are done :/ Is it fair?

Abdelmoumene and rsahak:
Consider the max loads listed as the requirements. With a factor of safety of 2 the required loads would be about half of the listed loads. The kick load requirement of 125 lbf is a general requirement for ISS items that might get kicked by astronauts. We realize that for ABS, 125 lbf might be unfeasible but make it as strong as you can. But, considering that a kick would most likely exert a compressive or flexural force (I can't imagine a kick exerting a purely tensile force) 125 lbf might not be that far out of reach.

Quincy Bean Thanks, but... I wanted to say that you can print support with the same printer nozzle and same material. It is just an option in slicer software. The point of my question is - let's say Elena prints something and slicing software adds some kind of support >>> http://tinyurl.com/nmlcr5o <<< so now she needs to remove it; is this kind of solution acceptable?

How should I use the maximum load specs expressed in lbf? I expected at least a psi. Moreover: could you better explain the "kick load" requirement, is it a 125 lbf force applied to the object in a random direction or what? Thank you for your attention.

Sharp Edge Human Factors & 3D Printing-
Working on my design I have came into some issues with Fillets on Edges. Due to the Nature of 3D printers, Fillets are very hard to print on the Bottom Edge of a print with out supports in the Z direction. Fillets are very easy to print on the XY plane. Would it be possible to Cut in a 45-60 Degree Chamfer and Fillet the upper part?

Quite a few entries, I'd just like to point out to everyone participating, this part is something that will be 3D printed, in space. There are some limitations with 3D printing on the ground, let alone in space....I would say that 80%+ of the designs uploaded would not be feasible or would require support material, and even then probably wouldn't work just due to complexity. This is not a challenge to design a clamp for NASA, the challenge is to design a 3D PRINTED clamp, big difference.

Do yourself a favor and research about 3D printing before spending all that time making a fancy design and uploading 5 versions of it.

To start with, remember that the 3D printer builds off of a flat surface, secondly, imagine the layers being added line by line, any angle past 45 degrees won't work without support material (you can bridge gaps, and this can work quite well here on earth, but even then it requires a bit of knowledge and testing, and that's not to mention zero G).

I have a question. The measurements of 1.379 in. and .754 in. of the blue oval in the picture provided are of the handrails? They seem to be a tad bigger when looking at the pictures of the astronauts grabbing on to them. Maybe is just the perspective in the picture. Thanks.

I have uploaded my design using the "Submit an entry" button, however my design has not appeared in the entires, but it has appeared on my profile. Did I upload it incorrectly? Or should I have used another method?

@ Hugh: This is a design COMPETITION, not a design collaborative effort. If it was then everyone contributing to this challenge would be rewarded, and that quite isn't the case. Also, I'm not crazy about the fact that you seem to be encouraging designers to borrow ideas from other entrants to be used in their own designs and find that way of thinking a bit marxist where a person's creative and intellectual property is concerned. It be wonderful to remove any sort of designer ownership from the designs that have the most likes, take what you want, and combine them into a winning design, wouldn't it. Will be interesting to see what you come up with as I would imagine you are planning on entering...right?

@ Jonathan: I'm not sure why you feel the need to take on the role of paternal 3D printing guru here. I've been 3D printing for over 5 years now on all kinds of machines and am quite happy letting the competition make as many mistakes as they like.

Dave, just giving some advice to entrants, that's all. Just seems like people aren't grasping that this needs to be 3D PRINTED, it's not a, design a clamp for the hell of it, assignment.

And, now that I've been 3D printing for a while, I realize the limitations. I see how some of the designs I made for 3D printing competitions before, were way off the mark because I didn't fully understand the process, not having a printer.....

With your 3D printing experience, even more so you'd have to agree, most of these designs would be pretty hard to print. But whatever, great eye candy anyway. No complaints there.

@Jonathan Have you ever came across the fracture mechanisms??? If so then you would agree that the infill structure is like internal flaws in a body. Singularity problems will not allow for a converged FEA solution. Plus in any case you will try to mesh such a complicate structure it will take forever. Nevertheless you can try to simplify your study with more than a couple of ways.
(AND NOT WASTE YOUR TIME) ;D
1- Quick act print a specimen similar to the one we use to determine the tensile strength and get the response in different directions (If you are aware of composite material analysis you know what I mean). Then use these data to build a material from scratch that will give similar response. Test and converge your simulation according to the real life testing results.
2-ANOTHER WAY try to analyse first your model considering it as an ideal uni-body. After being sure about your results and knowing the area of the max. stress you can try to transfer the stress to a small sample pattern of the infill structure. Do not expect to run and get answers on something very complex for the first time. This is a very long conversation and you will need to take in to account many assumptions.
But do not forget your big advantage!!! You already have a printer and you can cross-check any FEA results.

Of course even after all you will still have to consider some statistical error as nothing is perfect even when you 3d printing something. ;P

Happy to go dipper in this subject if anyone else is interested... Good Night Guys!

David, thanks for your comment, I have also noticed some designs seem very if not too similar, as for tensile strength a part made in gravity environment and a part made in a weightless environment will probably be different in the z plane, also the make, color, and extrusion temperature of the filament will change the results.
Good luck to all.

looking into FEA analysis right now, getting the hang of it, I've never played with the simulation feature that much but it's blowing my mind, it is incredible cool! there's got to be a way to cheat it to get a more accurate reading for an "infilled" part, what about using a different density, like for wood or something? has anyone experimented with this?

No much time to go through this properly until weekend...
However, if you don't analyse dynamics or not consider the gravitational force when conducting an FEA analysis the density is not part of the equation. I hope you get why?! ;D

Does Anybody know if the position of the seat track has to be the same as in the one from NASA's original HCA design (On top of the rounded side of the handrail)? Somebody made a comment on my project regarding that.
Clarification will be greatly appreciated. Thank You.

Uh huh, okay. There's just a lot of information out there on the interwebs which is more reliable than what I learned from that vid.
...
However, it looks like we use the same peripheral, Razor Nostrmo? That part was cool :)

"Not reliable"
Not sure what you mean? Can you elaborate.......It's a pretty straight forward video explaination a design flaw in the way I printed my design....I'm sharing so others will learn, incorporate this fact into their designs etc. etc. I don't claim to be a pro at making YouTube vids, they're fun to do though. Yes people can search the
"interwebs" but at the end of the day, I'm sharing what I've learned during this design process, and its more of a specific and targeted video to this competition, than what you could find online from a general search. I'm sure some eople will found it helpful, if you didn't like it, don't watch it. Simple.

I understand Jonathon! I think it is great that he tells people that a lot of the designs can't be printed and how to change that!
Could we get back to Juans Question :
Does Anybody know if the position of the seat track has to be the same as in the one from NASA's original HCA design (On top of the rounded side of the handrail)?

Jonathan,
I found your video helpful and interesting. It is great to see engineers being helpful to each other in a task such as this. Not everyone has a 3D printer to test their ideas.
Michel, Juan,
I have assumed that the track is supported from the rounded side of the rail.
Structurally this is the section of the rail that can take the most load.
Like a Universal beam in structural engineering, the long axis will perform better for bending and stress.
Perhaps NASA can confirm this?

@ Michel and Gerard, thanks guys for the feedback, means a lot. Hopefully it will help influence your direction and avoid any time wasting. Wish I could do it in other languages but I'm limited to English and French at present.
Feel free to PM me any quick questions about the 3d printing process also, Ilol do my best to answer them.

@Jonathan, Thanks fo the demonstration. Would be interesting to compare two sames pins one printed along its length, another perpendicular.

@Quincy Bean, Rephrasing what Rashiga Walallawita already asked you:

You mentioned "Maximum loads from mechanical properties we have obtained so far from ABS parts"..."Z Tensile (build direction): 50 lbf,"
What was the cross section area of the specimen you mentioned, 1 in x 1 in?

hey Folks, i got a question i can't get an answer out of the specs provided. can the Printer on the iss do Support geometry or is geometry dependent on the Extrusion axis. as far as i saw the Printer just had one extrussion head?

@ IVAN, that's what I am doing.....or I wanted to do until my printers hotend went caput....awesome how mechanical problems always happen at the worst times... :)
parts are in the mail, hope they arrive in time.

the pin will be much stronger printed sideways, horizontally, if you search the "interwebs"....*ehem... you'll find that it's pretty common practice to do that for critical parts, it's the downside of printing FDM, there's always work arounds though. Normally you would just use a bolt anyway :).

@ Jonathan if your asking the question it means the results are not certain, if the results are not certain the risk of a failed print is higher, if the the risk of a failed print is higher then why do it ? Bridging happens because pieces are badly designed.

If I am reading this correctly, the print resolution is 0.04", but the specification for the stud hole is 0.785 +/- 0.005" (MS33601). This tells me that the printer cannot create this feature accurately. Am I missing something?

@rsahak Very interesting, and nice foto on page 9. But Mamadapur thesis date from 2007 and B. M. Tymrak paper, the website is refering to, date from 2014. It seems that technology has evaluated, like they show in their paper a lot depend of printer model.

To Ivan Pankratov:
Yes of course.
1. For example, how to define the density of manufactured part which obviously depends from printer's settings (air gaps and etc).
2. Now, I am in doubts that without Young’s moduli and Poisson’s ratios for each axis will not be possible to define and therefore to move to simulation process???
Good luck.

@folks at NASA. Hi, I 'd just like to know if there is an ideal printing time range for the device that your looking to attain. Under 1 hour, between 1 and 2 hours, not over 3 hours, etc. I ask because I can print a device out as strong and resilient as you like or as fast as you like. However, having some sort of "printing time frame" value will greatly help with my calculations and determining the final FDM 3D printing parameters, thanks!

@folks at NASA: What I meant by my above comment was that if I had an idea of an ideal printing time range, I can correctly modify my entry file as well as provide the correct 3D printing parameters that would be required when printing out the device e.g. # of shells, wall thickness, infill%, etc. This will help me strike a good balance between the device's strength and the print time it takes to create it.

I'm using 30%, 3 shells on test mockups, 3D printed stuff is pretty weak until you get up into 80+% infill. My honest opinion, for something like this, probably should be 100% infill. Just think about it, you have little small plastic ledges (T Slot for the seat track) where the bolts fit into, a part that's normally CNC aluminum. Putting a load on those bolts is going to put ALOT of force on those thin ledges, even at 100% infill, I could see them ripping with more than 20+ lbs of force. I was going to test this out and post a video, but I have to wait for parts for my printer....:(

@Jonathan: Bridges are on of the things we're experimenting with so we're really not sure yet how it will handle bridges. I would suggest keeping the bridge to about 1/2 inch. Arches or domes would probably work really well too.

Andrew: In general 1 perimeter is used and the infill is solid. If a sparse infill is used it is generally 3 perimeters and 3 solid layers on top and bottom. The extrusion path width is generally between 0.4 and 0.45 mm.

I have a question about the stud...In the youtube video the stud has a dual circular base...Is this the type on board the ISS as shown in my rendering? Or is it a singular base? Obviously my design would depend on the answer although I have a few ideas for single base studs as well.

@Quincy, Drew:
In the “Seat Track Explanation” section it states “Your design should allow for the stud fastener to be attached and secured.” I just wanted to verify that the mounting adapter will always have an L-track stud that is secured with a nut, and never the spring-loaded clip type of fitting that is captured by the 0.785” hole but is otherwise loose and can rattle in place. Thanks.

@Dennis Pak:
It is hard for me to say "never," but for this challenge the assumption of a rigid nut type faster is an acceptable assumption. Please take note that even with the nut attachment the washer beneath the nut still interfaces with the 0.785" hole. The sliding along the track is not really prevented by friction, but by mechanical interference with the 0.785" hole.

@Nasa Folks:
Is there a minimum clearance distance spec between the ISS interior wall (that the hand rail is mounted to) and the nearest rounded surface of the hand rail? From the image it looks like it's about 2 inches. Please confirm. Thank you!

@Drew Hood
Is it safe to assume the nut type fastener used on the ISS uses a washer of approximately the same size as the washer shown in the video, i.e. a washer ≈ 1.125" in diameter and ≈ 0.125" thick? These dimensions do not include the portion that interfaces with the 0.785" hole.
The photographs of the current hand rail clamp and seat-track seem to indicate this is true.
Thanks

Is there additional clearance or tolerance we should add in addition to the tolerances given in the drawings? My experience with 3D printers is that there is an additional clearance we have to account for due to the accuracy capabilities of the 3D printer itself.

as mr.Drew Hood mentioned before.....the focus is on strenght. some seem to have ignored the requirements and material specs at all. at least that will shorten the evaluation process. this is, for good, not a drawing contest.

I made two studs for testing my design. Hopefully somebody benefits from them. Just to be clear, I made them as accurately as I could, they might not be exactly as the ones NASA uses. I believe stud3 is more accurate. https://grabcad.com/library/studs-for-nasa-challenge-1

Good luck everyone and thanks to NASA for what has turned out to be an exciting challenge and opportunity. Almost 500 entries, Wow! BTW-if anyone is interested I've uploaded a video showing how we do 3D printing in da' hood, lol

If it weren't for so many great designs I would have been happy with my first entry, it just goes to show how great this design forum really is. Even in the corporate world I couldn't imagine pooling together such talent and pushing them to such a level of competitiveness without millions invested in development.

It has really been a pride to work for NASA, thanks.
I do not think you win any awards, as there are very good designs, but if I would like to know that since I've been in the standings, just for personal satisfaction.
I hope it is possible to know, thank you very much GRABCAD.

no, not sure how NASA will do it, they've stayed pretty low key on this thread.
has anyone seen this video??? Jerry test's out NASA's space wrench.....they should have come to GrabCad for this, we would have killed it.

One concern that I have with some of the test results is that the printed rail and the printed clamp are printed with the same layer orientation. The steps amplify the clamping results. That is why I printed my rail on its side so that the print layers are not skewing the results and more accurately represent the aluminum rail.
Obviously I think the flex gripper should be considered: Flex gripper

@ Rob, kicking them off the rail can be applied to any plastic clamp that had to meet their specs, even if it was injected molded. It's sort of implicit :) You're talking about replacing a CNC component that's thin to begin with, with a weaker material, plastic. That was the whole challenge, the whole point was to design the best and strongest clamp within the parameters given, to atleast come close to matching the strength of the original materials and design...I don't think anything thought we could beat CNC machined metal lol :)....that was fun part, seeing how CLOSE we could get!

@ NASA, trusting your judgement on the picks, can't imagine how hard it was. I appreciate making finals. I feel really good about my design and I have no worries that it will perform to spec for your personal testing! Actually curious to see what it's limitations are as I didn't have a chance to push it too it's maximum.

Lotta hard work, lot learnt, all in all a great challenge for me personally, one of my favorites to date.

Ya well I hear ya. And um, well I guess I'll thank you for the indirect promotion and compliment... I usually try to refrain from commenting on other designs if I'm part of the finalists...:)

Um, let me put it this way, I think there a few in the finalists that are promising, but out of the 490, there were also atleast 50 that could have easily worked well.....but makes it tough when you have so many good entries right...just gotta trust the client's judgement, they know what they want. But I guess if one of the clamps breaks, causing an astronaut to hit a switch which then sends the ISS into a catastrophic re-entry orbit and it crashes down to earth, it's our problem too :p

Yes I understand the design and maybe the rendering is a little lacking, is this a rendering contest? I can do pull ups off of any one of my entries while beating them with a hammer in any direction and was not even considered so maybe it is just a gimmick?

Congrats to all the finalists! This was a great challenge, I really thought I had a chance when my design went front page on grabcads community page and I got 53 likes. I guess the lesson for me is to work on my presentations, solid CAD isn't enough when you have so many strong competitors.

Here's the link just in case maybe the judges meant to include mine and missed it :)
NASA CLAMP

3d printing rule number one OVERHANGS need support material, if you look closely at the runners up they all need support to print. some of the best designs that can really be printed with no support and respect the print orientation rules for strength are not included, Why ??? Does NASA and grabcad really understand 3d printing or are the results influenced by other parameters, if that's the case progress will be slow, I suggest that NASA and "made in space" take a closer look at the results.

Yes I think you have found the answer, but if that's the future for space travel, we are not going far soon. It's a shame that real engineering is being taken over by little details and NASA suprised me with the results. Not to mention " made in space" who are supposed to be experts on 3D printing.

Ah shiny, NASA written in big letters, I wonder how much money will be wasted on all these little details, Is this really the future ? I had faith in grabcad but it looks like real engineering has no future in this world. As you said a bitmap of the world and a big logo NASA is all you need to become the best engineer.

Just been an analising the runners up, Adam you are right "not enough likes" it seems that NASA and "made in space" are more influenced by "Likes" than usability and productivity, what a shame, 3d printing requires an aproche to design that is different from conventional machining and I really was convinced that NASA would take this into account, not the case apparently.

I think the "shiny design and rendering" outweighed practicality. I do want to point out that Champs v3.03 uses the exact same principle and base design as mine: Compression Clamp and was posted about 27 hours afterwards. It is much better presentation. I am not saying he copied it, but his design certainly wasn't unique in the class. I find it odd that is the quote given for the choice. Given I placed my focus on the strength, as required, I feel mine should at least be tested with his to prove the concept. They should provide the weighting charts they used to pick the designs as it would help people with future efforts.

I think the judges should be questioned. it's blatant liberal diversity political correctness BS results. the judges are all "yes" men/women in corporate America who have "no clue" . they are an example of exactly why I retired. LOL

Congrats to all the finalists and thank you NASA for sponsoring this exciting challenge. Myself and others hope you've enjoyed your experience here and hope you come back soon to give us more opportunities to design and create. I do however, have a few concerns about the finalists, some theories on their functionality, as well as the "uniqueness" that seems to be shared by a few of the entrants. Always the curious and fevered mind, I am currently printing them all out to see if my elementary assumptions are correct.

In any case I, like most of the folks here at GrabCad, am always trying and hoping to improve both my engineering skills as well as my creative ones and enjoy getting feedback both positive and negative about my projects in the hopes that I may actually win one of these things one day. Particularly what I may be doing/have done wrong as well as what makes my particular model stand out. That being said, while I never expect to win any of these things, I do to some degree expect to do well, especially if I get significant positive feedback on what I consider a solidly designed, engineered, and functional entry. In this case, I can't quite figure out what it was that I did or did not do to not be considered a finalist. If there was something that I missed in the spec or designed incorrectly, or if you just thought it to be plain ugly, I wouldn't mind one of you guys at NASA letting me know. I would greatly appreciate it, thanks!

Pretty sound arguments here. Although I feel orientation is trivial as it can be turned very easily, and even the seat track is an easy modification I would consider an easy fix. What was stressed is strength, particularly 125lb kick with a FOS of 2, you would think that would be the first weeding out criteria. These were your specifications which I feel I achieved and I see a few others have as well yet appear to have been overlooked. "The current clamp assembly (shown for reference) has a required kick load of 125 lbf. We understand that this requirement may be unfeasible given ABS material and the size limitations, but try to make the designs as strong as possible"

In any challenge like this there are obviously going to be disappointed engineers.
But the judges seem to have made life difficult for themselves.

Take for example one criteria,

***********************************

The CHAMP MUST AT A MINIMUM meet the following requirements:

3. Shall conform to the following sharp edge human factors
- Exposed edges 0.25 in thick OR GREATER (THAT IS EVERY CORNER) shall be rounded to a minimum radius of 0.12 in.
- Exposed edges 0.12 to 0.25 in thick shall be rounded to a minimum radius of 0.06 in.
- Exposed edges 0.02 to 0.12 in thick shall be rounded to a full radius.
- The edges of thin sheets less than 0.02 in thick shall be rolled or curled.

***********************************

This should have been an easy criteria to utilise to check each submission.

If there are sharp edges or corners they cannot be accepted.
After that whatever is left is accessed for strength, etc….

Now take a look at the finalists.

A very interesting challenge and well done to everyone who took part.
Congratulations to the finalists.

Robert you are correct if the part is turned in the XY plane, the Z axe is always the weakest as it no longer uses the physical strength of the material but sticking or gluing strength, all of the chosen designs except 1 are printed with the axial pins in the z axis so they may work once or twice but the axe would give eventually. I agree that the seat rail could easily be modified but any good design would have also taken into account the seat rail strength and used this to it's advantage. Therefore modifying this now would change the physical properties of the champ for the better or the worst. For example the design CLIPPY how could this be modified for the bolt used ???? or the PT handrailclamp this would need one end opening up for ISS bolt to be used weakening it considerably.
One last comment.
NASA has standards that are very very strict because
1 they put people lives at risk and
2 they must have an international compatibility between parts.
This means that even the most mundane dimension or feature becomes very important, so how could they chose entries that need serious modifications before they can use them ??? it makes no sense at all. Many of us engineers were happy to see a real competition coming from a sentinel in the engineering field I personally feel let down by the current results . Maybe we should enter a beauty contest next time instead of racking our brains for nothing.

Looking at the review note "...Did we leave anything amazing off the list? See something we should know about? Let us know in the comments!"
To the members of the jury, I would like to challenge you to find any entry with a One-Handed Interaction Operation concept like the one I submitted.

Additionally, (as part of my entry) I included a spreadsheet document listing all the minimum requirements from the specifications of the challenge. I would also invite you to fill it up as a reference. I have updated the document with the finalists, ready to be completed. You can download it here:

Congratulations to the finalists. Like the other submitters that didn't make the list I am of course disappointed. I am wondering if there was any consideration to the timing of the submissions. It appears that some of the finalist designs built off of or were very similar to earlier designs. Collaborative design is desirable in the workforce to generate the best result. However, in a competition, perhaps it would have been best to show the designs only after the submission deadline had passed.

Thank you for the feedback everyone. We had a lot of amazing entries and deciding amongst them was very difficult. The finalists were selected based on the CHAMP figures of merit including the Total Material Usage, the Number of Prints Required to Complete Each CHAMP, the Handrail Connection, and the Seat Track Connection. As we go forward with the process and select the 5 winners, we be looking at these entries in depth and ranking them based on these metrics. When we release the winners we will offer more comprehensive comments regarding why each of the winners was selected. If you have any other concerns, feel free to contact me at ben@grabcad.com.

Hi. I wasn't really planning to get involved in the discussion above, but I strongly agree with the earlier comments regarding the fact that "printability", compliance to specification and the time of design submission has not been weighted as deciding factors when selecting finalists.

If I should participate in future GrabCAD challenges then I will wait with submitting my design up until the deadline to be on the safe side.

Anyhoo, I wish the finalists the best of luck and you are already winners as far as I am concerned, well done!

Everyone would like to have his design chosen, but there we're 485 entries. I'm sure they chose good ones even if the best ones maybe we're left out. But you have to know even the best product won't sell if the advert is no good. And the entry had to be complete allround because this is not a kindergarten but a community of hungry wolves. It's a competition.

I'm a fan of Mark fuller's and Micheal Heberts designs.... anything using pins printed in the Z direction I couldn't support, both Mark and I have learned this through the research process on our own designs, they WILL hold weight, just not for long.

Again, I would like to thank everyone for their feedback. If you have any concerns, please email me at ben@grabcad.com. I would like to keep any further comments on here constructive and positive. Since I feel like we've covered all that needs to be said regarding the selection process, any further discussion on this topic will be removed. Let's remember that all of the finalists worked very hard on their submissions as well!

I can't believe this reactions here. 'doesn't fit in the printer bed', 'doesn't interface', 'doesn't have some requirements' 'has to be modified' etc. Nasa has chosen the designs based on working principles, details are not important! Neither of the designs will be perfect and can satisfy NASA's demands. They will have a look at the working principles and the possibility of combining some (smart) features of the designs in a next level future champ. Congrats to the 14 finalist, and for the ones that were jealous in the previous comments: try to be positive, it was a nice competition and I'm sure that you've learned a lot from the design that you've made or at least you can learn something from the other 484 design that were participating.

@Mark, Details are important, we are designers and engineers, that is what we do!
Meeting the minimum requirements of a specification is the way we work and
If we do not meet the criteria then so be it, we accept the outcome and move on.
Otherwise we could be artists and small details would not matter.

Constructive comments on the selected finalists was asked for and given but should never become unprofessional or personal. It begins to sound like a sore loser.

Congrats to the winners, to organizers and all participants!, its been so interesting to see so many "schools of thinking" at work :), its been a privilege to race with you guys :).......and most important ....let's move on :)

@Gerard, I totally agree with you that details are important in designs. But in this competition, a really clever design with an incorrect interface to the seat track can beat an other design that does meet the requirements, but has less clamping force or uses twice as much material. ( for an example)
thanks for the congratulation b.t.w. :)

Before I started with my concept I didn’t think about the restrictions of 3d printing but about the opportunities and advantages 3d printing enables. The “Nasa wrench” is the best example: it can only be 3d printed, not be made by conventional means and it can be used straight from the printer.
With this inspiration, I tried to think “out of the box”, I designed prototypes and after a lot of testing and adaptation the “Project Rigel CHAMP” was the result. I already listed all the advantages of my clamp but I can also say that is one of a kind. (Feel free to comment my design)
After the “sales pitch”: Think more about the opportunities of 3d printing. For example: Open community of designers, open source designs and a 3d printer on Mars :) There will be so much to design that everybody gets his design to Mars :)

- My idea was conceptually original (no one else try it).
- Not required support material to print (I proved it)
- It can be installed with one hand.
- It complies with the requirements.
- And YES it works.
Either way I send you a "BIG-HUG". Clamp: Big-Hug

Hi all, I've downloaded a number of the finalists entries and made videos of my testing of them as I said I would, but stopped halfway through as, well...I'll leave it at that. I was going to release the videos on my own but decided instead to leave it up to the GrabCad community. I've just uploaded a project called "My NASA CHAMP Challenge Evaluations" that can be found here: https://grabcad.com/library/my-nasa-champ-challenge-evaluations-1 If I get 2/3 of the number of remaining entrants - 1(me) in likes for this model (which as of this writing equals 316 likes), then I will release the videos. That will mean, at least to me, that there are a significant number of folks who still do care about this challenge and in possibly making the jury's decision a bit more transparent. If not then that will be the end of it. I had thought that I personally would have gotten some answers as to why the jury picked what they did after going through this process, but was left with way more questions than I had anticipated. Maybe if the videos get a chance to see the light of day, someone may be able to answer them for me. That however, is entirely up to you guys.

ok, up to you...I'm going over your model right now, ChampLock..wouldn't mind seeing what it can take as far as static load....yes...i'm obsessed with how much weight I can hang off of these things... from first glance, looks good, but there might be an area of issue. I'll attach a picture on the model page in a second or two.

Actually, I want to revise my previous comment. What I found was what APPEARS to be that most of the finalists' entries do not meet those first 2 minimum requirements outlined by NASA in the challenge. That is what I hopefully will be able to show everyone else so that myself and others can have an open and unadulterated discussion about this challenge and NASA's seemingly interesting selection process...if only a few people care, then what's the point?

Well, first congratulations to all finalists!
With 493 entries for a contest it,s clear that there are more workable solutions than could be chosen for final. In same time most participants believe their design is the best,myself included :), but it's not the reason to adapt a "sore loser" attitude. It,s unrealistic to expect from NASA to go trough all 493 entries in such short time and be unmistakable in their judgment. Meanwhile will wait for NASA more comprehensive comments on their winners selection and support #David initiative for an independent test, i guess it will help choose winners among finalists .

What a downer that negativity. Would also participated if the main prize was a baseball cap with NASA logo. I'm just afraid to express my joy, to be a finalist.
.
F**t, Joepie....
Congratulations to all finalists, am looking forward to the final result.

not enough people designing for the fun of it and ENJOYING what they're doing...

too many people going "ME" "ME" ME" and not "OUR".

too many people trying to PICK APART designs instead of saying, YES, WE KNOW THE FINALISTS AREN'T PERFECT, LET's HELP THEM MAKE THEM BETTER.

in my video I clearly show the weaknesses in my clamp design, is it perfect, no, is it a GOOD design that can withstand a helluva lotta weight and beating, YES.

I'm lucky to have made finalist, but now, I'm calling on YOU to be apart of this and help make this clamp design, and some of the other finalists, the best they can be, stop saying "ME" "ME" "ME" and sulking, and let's work together with my design and the finalists to make them the best they can be.

Hi everyone. We will be releasing a list of honorable mentions when announce the winners. Additionally, I wanted to clarify one of the finalist designs. We mistakenly announced an earlier version of Gergo Graf's "The Grabber" as a finalist instead of his second version. The results page has been updated accordingly. I hope everyone is excited to find out who the winners and honorable mentions are soon!

"Over the next week, participants are able to voice their support or concerns."
And a few finalists delete my posts, that's great! (But thx to those who answer)
Handrail Clamp keyholeSimple new seat track. But the clamp has to be tested. The main problems I see are:
1.How do you remove the clamp?
2.Are these teeth printable with the resolution of the 3d printer?
3.Wear of the teeth?

@Michel Scho: Right I have removed spam comments of only two people, who complain about everything. And recommend/spam their own entries in the final submissions comments. I am that negativity and nitpicking a little tired.

The only one among those that you chose answers the criteria required in my opinion. Twist-N-Lock NASA Handrail Clamp is my choice because it is the only one whom you will like using and whom the exercised strength is adjustable. If you need a more beautiful design, it is easy to modify slightly. The mobile room part can remain on the first screw not to lose it. I'm sure you need a rotation mecanism in this 3d print challenge.

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